1. Technical Field
Embodiments of the present disclosure relate to mixed light apparatuses, and more particularly to a mixed light apparatus for a liquid crystal display.
2. Description of Related Art
Liquid crystal displays (LCDs) are extensively used in a variety of electronic devices. However, LCDs are not self-luminescent, therefore, backlight modules are required to illuminate the LCDs. Generally, the backlight modules can be categorized as direct structures and edge structures. Because the direct type backlight module can provide better illumination in comparison with the edge backlight module, direct type backlight modules are more widely employed.
One such direct type backlight module 10 is disclosed in FIG. 1. The direct type backlight module 10 includes a substrate 11, a light source 12 and a diffusion plate 14. The light source 12 is disposed on the substrate 11. The light source 12 may employ a plurality of point light sources (e.g., light emitting diode (LED)) or a linear light source (e.g., cold cathode fluorescent lamp (CCFL)). An LED array is extensively employed as the light source 12 for LCD because the LED has merits of deprivation of mercury pollution, high color saturation and long lasting. The diffusion plate 14 is disposed above the substrate 11 for allowing the light emitted from the light source 12 to be uniform and providing light for an associated display panel.
The LED array consists of a plurality of red LEDs 12a, green LEDs 12b and blue LEDs 12c. The LEDs 12a, 12b, 12c are uniformly spread evenly on the substrate 11 according to the color of emitted light. Particularly, rows of red LEDs 12a, green LEDs 12b, and blue LEDs 12c are arranged in alternating fashion. Red, green, and blue light, is emitted from the light source 12 and mixed continuously until reaching the diffusion plate 14 to produce white light. A predetermined distance between the light source 12 and the diffusion plate 14 is required for mixing the emitted light and providing uniform illumination.
Recently, because of an increase in demand for thin and lightweight LCDs, the distance provided for mixing emitted light has shortened, resulting in poor mixing and producing yellowish bluish light rather than the intended white light.
In addition, when a large number of red, green and blue LEDs are utilized for large-scale LCD production, the white light emitted from such an LCD has low energy and low color saturation. Moreover, the color of mixed light in such manner cannot be adjusted as desired.
What is needed, therefore, is a mixed light apparatus for providing adjustable color light and having improved color saturation, improved uniformity, and high energy.